You want to create an illusion of space but in order to do this and not give a stark feel, you should avoid painting walls white. High Gloss white or Cream make for an easy clean, bright accent trim for mouldings. If you are selling your home in the winter and you are going to paint in advance of placing your home on the market, you could consider all the warm tones, including a yellow for the kitchen. Yellow is cheery and brightens the room, especially if there is low light and not too many windows to bring in natural light. A Terra Cotta tile or accent color in the same room brings the earth tones into your room and creates a natural feeling warmth. If this is too bold for you, the use of these color tones in cushions, placemats or even the utensils in the kitchen can achieve the same effect.
If you are selling your home in the summer, then I would choose cooler colors for the bedrooms and bathrooms to create an airy, breezy, spa feeling. Every one wants to be re juvenated in the Spring and Summer. Cool greens work well in entrance foyer's, bedrooms, family rooms and again you could use the yellows in the kitchen however a cooler tone would be the better choice.
Greens are a good choice for an office and inspire concentration. If using greens and on the cool tone side, white trim would be a good color. If using warm greens then a creamier trim would be in order.
When in doubt look to the colors of nature and they will blend into your home beautifully. Bright colored cushions and large accent pieces can be your friend. Rather than using two or three small ornaments for decoration, be bold and place one large interesting piece on top of a coffee table, couch table or in an alcove, that is in the line of vision.
You want your home to stand out as spacious, clean and most of all welcoming to a potential Buyer.